<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
	pageContext.setAttribute("username", "admin888");
	request.setAttribute("age", 18);
%>

<p>
用户名：${username }
</p>
<p>年龄+1：${age+1 }</p>
<p>空值处理：${password }</p>

<p>${pageScope.age == null }</p>
<p>${empty pageScope.age }</p>
<p>获取项目根路径，用于解决web编程中的url引用问题：${pageContext.request.contextPath }</p>
<%-- 相当于在调用request.getRemoteAddr()方法 --%>
<p>获取访问者ip：${pageContext.request.remoteAddr }</p>
</body>
</html>